This invention relates to an air bag cover assembly for use in an automobile in overlying relation to an inflatable air bag cushion. More particularly, the invention relates to an air bag door construction including an arrangement of integral hinge elements which are arranged so as to produce a controlled deployment geometry in the air bag door upon inflation of the underlying air bag cushion.
It is well known in motor vehicles to provide an air bag module which includes an inflatable air bag cushion for the protection of a vehicle occupant in the event of a collision. The air bag module typically includes an inflator for discharging an inflation medium such as high pressure gas or the like into the air bag cushion upon the occurrence of a predetermined level of vehicle deceleration or other measurable vehicle condition.
Inflatable air bag cushions may be located at a number of locations within the vehicle so as to provide protection for the occupants therein during various collision events. In particular, it is known to utilize an inflatable air bag cushion deployable from the dash panel of a vehicle in substantially opposing relation to a passenger within the vehicle during the collision event. In order to facilitate the deployment of the inflatable air bag cushion from the dash panel, the dash panel is typically provided with an opening therein which is covered by a displaceable cover assembly. Such cover assemblies typically incorporate a substrate material such as metal or plastic which may be covered with a foam and/or a decorative skin layer so as to provide a substantially continuous surface across the dash panel. One such cover assembly is illustrated and described in U.S. Pat. No. 5,382,047 to Gajewski the teachings of which are incorporated by reference as if fully set forth herein.
In order to facilitate the deployment of the inflatable air bag cushion from beneath the dash panel, it is known to incorporate a weakened break-out pattern across the substrate to define a hinging door within the cover assembly which is displaceable upon the application of force from the underlying air bag cushion as the cushion expands outwardly.
Upon displacement, the door assembly which is made up of a portion of the substrate and covering materials opens in a hinging manner so as to swing upwardly. During this hinging movement, the door structure typically retains its shape characteristics such that the edge closest to the occupant swings upwardly and away from surrounding portions of the dash panel in a well defined arc.
The fixed arc displacement of the door panel has been found to provide adequate deployment characteristics for the underlying air bag. However, the space requirements associated with the movement of the substantially rigid door may affect the freedom of design of the instrument panel and may also have an impact on the freedom of an occupant to be positioned in extremely close proximity to the door structure due to the fact that adequate room must be maintained accommodate the swinging arc.
According to one aspect, the present invention provides advantages and alternatives over the prior art by providing an air bag cover assembly including a displaceable door structure which hinges away form the surrounding cover structure while at the same time undergoing internal deformation in a predefined manner so as to reduce space requirements for the hinging displacement.
According to another aspect, the present invention provides an air bag cover assembly including a displaceable door structure incorporating an arrangement of integral hinge elements disposed within the boundaries of the door structure inboard of the perimeter of the door structure so as to give rise to internal tuned deformation of the door structure as an underlying force is applied by an inflating air bag cushion.
According to one exemplary embodiment, an air bag cover assembly is provided including a substrate panel having an air bag deployment opening disposed therein. A displaceable door structure is disposed across the air bag deployment opening within the substrate panel. The door structure is defined by a break-out pattern extending along perimeter edges of the door structure such that upon the application of force to the door structure from an underlying air bag cushion the door structure may open in a substantially hinging manner. The door structure is provided with a pattern of integral hinge elements disposed inboard of it""s perimeter which define living hinges so as to give rise to controlled deformation of the door structure during the hinging displacement.
Other advantages and aspects of the present invention will become apparent through reference to the following detailed description and/or through practice of the invention as described therein.